12DPO-14DPO

Unprotected sex during prime ovulation. Something is really off with me. Looming headaches. Cramps. Tired. Weight gain. Everything but sore breast’s. 12dpo I thought AF started as bleeding came and was a bit heavy. 3 days later it’s stopped. Almost completely. A little light pink watery. I feel sick. All of my tests have been negative but I haven’t tested in a few days. My period has never been this short. Ever. Also I’m crying a lot and my dog is not leaving my side. At all. Is this implantation? Prior to all of this and still currently tugging feeling in abdomen. I haven’t tested since 12dpo.